There are many amplifier standards. Instrumentation vs audio amplifiers also have different standards. So which is the most enjoyable amplifier standard. Heres another way to do the symef by our standards.
According to post 1177 and 1178, here's celebrating symef in all its diversity. It is important to let your ears decide. One thing to consider is..If one thing came apart, would the whole amplifier come apart? Type 4 is life on the fast lane. There's a good reason gen 1 to gen 3 SYMEF owners don't get separated from their amplifiers.
Dr Stephens SYMEF is the SYMEF type S that Thomas also has. There are a couple of diyers offering symef gen 1 pcbs online cheaply on aliexpress and other sites, I dont know them or the quality
The sound signature of post 1181 and 1183 are close and inline with 1diffqc although 1diffqc may sound better to some. 1181 has higher stability than 1183. Post 1 is the original symef and some say it has beautification inbuild
This is simplified Hafler P700 with different output stage..
Current through D13 is 36mA. 5mA will be sufficient. R33 should 5k6 or more. As it is both of them are dissipating way to much heat.
Otherwise, it's interesting. Hafler P7000 supposedly sounded very good..
With 10mS between charges for full wave rectification. Do 8 ohm speakers sound better with linear supplies than 2 ohm speakers? How much ripple is too much and how much is acceptable
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For those asking about the specs , here we go
SYMEF type S
Specs per channel dual mono 300VA AS-3435 - 300VA 35V TRANSFORMER each
64 Watts 8Ohms 0.01% THD (16000u per rail)
128 Watts 4Ohms 0.02% THD (16000u per rail)
172 Watts 2Ohms 0.04% THD (24000u per rail)
SYMEF type S
Specs per channel dual mono 300VA AS-3435 - 300VA 35V TRANSFORMER each
64 Watts 8Ohms 0.01% THD (16000u per rail)
128 Watts 4Ohms 0.02% THD (16000u per rail)
172 Watts 2Ohms 0.04% THD (24000u per rail)
Suitable power supply capacitors https://www.digikey.com/en/products...er-electronics-cde/382LX333M080B092VS/2256594
https://www.digikey.com/en/products/detail/nichicon/LNT1K333MSE/2549067
SYMEF TYPE S
AN-5440 - 500VA 40V X2 TRANSFORMER DUAL MONO per channel
120 Watts 8Ohm 0.01% THD (33000u per rail)
209 Watts 4Ohm 0.02% THD (33000u per rail)
306 Watts 2Ohm 0.05% THD (33000u per rail)(Transformer overdrive by 1.5, manufacturer accepted rated overdrive 1.2,efficiency < 50%)
SYMEF TYPE S
AN-5445 - 500VA 45V TRANSFORMER DUAL MONO per channel (Amp Resting +/-63volts)
165 Watts 8Ohm 0.01% THD (33000u per rail)
277 Watts 4Ohm 0.02% THD (33000u per rail)
417 Watts 2Ohm 0.06% THD (33000u per rail)(Transformer overdrive by 1.7, manufacturer accepted rated overdrive 1.2,efficiency < 50%)
https://www.digikey.com/en/products/detail/nichicon/LNT1K333MSE/2549067
SYMEF TYPE S
AN-5440 - 500VA 40V X2 TRANSFORMER DUAL MONO per channel
120 Watts 8Ohm 0.01% THD (33000u per rail)
209 Watts 4Ohm 0.02% THD (33000u per rail)
306 Watts 2Ohm 0.05% THD (33000u per rail)(Transformer overdrive by 1.5, manufacturer accepted rated overdrive 1.2,efficiency < 50%)
SYMEF TYPE S
AN-5445 - 500VA 45V TRANSFORMER DUAL MONO per channel (Amp Resting +/-63volts)
165 Watts 8Ohm 0.01% THD (33000u per rail)
277 Watts 4Ohm 0.02% THD (33000u per rail)
417 Watts 2Ohm 0.06% THD (33000u per rail)(Transformer overdrive by 1.7, manufacturer accepted rated overdrive 1.2,efficiency < 50%)
Most amplifiers are voiced as tweeter amplifiers due to customer preferences. If you notice many amplifiers have no bass definition and are difficult to use when mixing bass or drums, bass sounds like a single muddy tone. The next batch of amplifiers are voiced as midrange amplifiers. Very few amplifiers are voiced as bass amplifiers. But we do have Chameleons for example here's the voicing for the amplifier in this post https://www.diyaudio.com/community/threads/symef-amplifier.198500/post-7418716. It will get you there but it isn't a king but a prince its more like a full range speaker. There's a cult following for such voicings.
Many sceptics are slowly coming to terms to the fact that SYMEF might never be dethroned. 😉.Reproducible facts speak for themselves
They are 33,000 nichicons. Both the Kemet and Nichicon are quite favorable power supply capacitors
How good are popular current and voltage references, should we care?
Not most can beat the 1n4148 https://www.diyaudio.com/community/threads/morpheus-ultra-low-thd.406485/post-7601404
Not most can beat the 1n4148 https://www.diyaudio.com/community/threads/morpheus-ultra-low-thd.406485/post-7601404